Although most people can provide you with scarcely more detail about the human brain than its existence and approximate location, one Left-Brained / Right-Brainedof the most popular brain-related facts they often report with great certainty is that they are either Left- or Right-Brained. More specifically, "Left-Brained" people describe themselves analytical and logical, with a penchant for mathematics, while the "Right-Brained" report being creative and emotive, with more artistic and intuitive personalities. These self-reports are fraught with problems…not the least of which is the fact that the entire notion of “Left-Brained” or “Right-Brained” people is complete bunk.

A quick Internet search for “Left-Brain/Right-Brain” tests results in literally thousands of options. A popular gimmick for team-building exercises and introductory psychology classes since at least the 1960s, these introspective measures almost always result in a personality type that the participant agrees with. That is because, like so many tests of this kind, the product is simply a reflection of the information provided by the participant. In other words, rather than measuring some hidden, truthful behavioral tendency, the quiz simply echoes the answers you provide. As a result, you will tend to agree with it, and assume that it has somehow looked deep inside and found the “real you.”

More scientific examinations, such as the March 2013 article by Jared A. Nielsen and his associates at the University of Utah, provide a less positive evaluation of such claims. In the study, Nielsen and his colleagues analyzed data for 1011 individuals between the ages of 7 and 29 years, measuring functional lateralization for each pair of 7266 regions of their brains. Their results showed no sign of Left-Brained or Right-Brained manifestation. "We just don't see patterns where the whole left-brain network is more connected, or the whole right-brain network is more connected in some people," Nielsen said.

But, if scientific evidence is lacking, where did this widely held belief come from? We may never know for sure, but some believe that it may have begun with a misconception over some important, Nobel Prize-winning research done by Roger Sperry in the 1960s. Sperry was studying patients with epilepsy who had been Roger Sperrytreated with a relatively experimental procedure known as “split-brain surgery,” in which the connective tissue between the hemispheres of the brain (the corpus callosum) had been surgically severed to eliminate serious, life-threatening seizures. What he found was that, after the surgery, the left- and right-hemispheres could no longer exchange information, leaving the patient unable to communicate. Through subsequent research with these patients, Sperry was able to discern which areas of the brain were largely responsible for activities such as language, mathematics, drawing, etc. Well-meaning, but misguided, enthusiasts have apparently taken these findings much further than the data allow, concluding that one side of our brains may “dominate” if we have a particular interest in, or affinity for, certain of these abilities.

So, the next time someone suggests that you are a logical “Left-Brained” person, or that you’re a creative “Right-Brained” individual, you might want to consider informing him or her that you’re a skeptic. And, as a result, you use your WHOLE brain at all times.

SkepTalk: Berkeley

If we build homeless housing, won't that just attract more homeless people? I read an article about this cool thing they're doing in Utah, why don't we do that? And what about tiny homes?

Significant research has been done on the causes of and solutions to homelessness, but public knowledge is based more on anecdotes and personal observation than on the social science. This talk will look at some of the most common misconceptions and provide a nuanced, evidence-based response on one of the country's most pressing issues.

WHO: Carrie Ellen Sager, J.D. is Senior Homelessness Program Coordinator for the county of Marin, where she works with local nonprofits and city and county governments to create a coordinated system of care to house the most vulnerable people experiencing homelessness. Prior to working in Marin, Carrie worked for HomeBase, a nonprofit law firm that works with cities and counties to implement responses to homelessness. She has a J.D. from American University Washington College of Law.